New Insights on Breast Anatomy Based on Magnetic Resonance Imaging and Surgical Observations.

Understanding anatomy of breast connective tissue is critical in contexts such as surgery and biomechanical modeling of breast deformations. Current descriptions remain contradictory and fail to explain breast biomechanics. We described the anatomy of breast connective tissue based on Magnetic Resonance Imaging and surgical observations. This prospective study was conducted at the breast surgery department of Montpellier University Hospital. A total of 196 patients were consecutively included between March and May 2022; 10 had breast MRI in 3 different positions (supine, prone, and lateral). Superficial fascia (SF) creates a "pocket" surrounding the breast, both anteriorly and posteriorly, as a consequence of dorsal development in the anterior body wall. SF appears to delimit two compartments of adipose tissue: a superficial and a deeper one, both crossed by retinacula cutis (RC). There is no continuity between the RC of both layers and therefore no RC running from the pectoralis major to the skin. An "anchoring ring," corresponding to a dense zone of connective tissue around the periphery of the breast, where the SF and deep fascia meet, is the main adhesion of the breast to the chest wall. Breast is shaped by the superficial fascial system and anchored to the chest wall at its periphery. It does not seem to be two distinct layers of SF and suspensory ligaments running through the breast from pectoralis major to the skin. Further studies based on these findings could evaluate the impact on biomechanical model performances. Surgeons should consider this description in order to optimize cosmetic results. Trial Registration: ClinicalTrials.gov identifier: NCT05301998.